Netlify-cms: Netlify CMS, self-hosted Gitlab, localhost redirect URI included is not valid

[blubberbo]

I am trying to Netlify CMS and a self-hosted instance of Gitlab. I went to the Start with a template on the Netlify CMS site and created a Gatsby project and automatically deployed it to a cloud-hosted version of Gitlab I have access to and everything worked fine. I then wanted to move it to an offline environment where I have another self-hosted, on-prem version of Gitlab so what I did was:

1. Cloned the repo from the live gitlab
2. Added the on-prem Gitlab as a remote
3. Pushed the repo to the on-prem Gitlab

Then in order to run the project on local host I did:

1. npm install

2. created an application on the on-prem Gitlab with the following settings:
   

3. changed the config.yml to:

name: gitlab
  repo: Syd/netlify-cms-test # Path to your GitLab repository
  auth_type: implicit # Required for implicit grant
  app_id: ********** # Application ID from your GitLab settings
  api_root: http://gitlab.sq.tlm.cloud/api/v4
  base_url: http://gitlab.sq.tlm.cloud
  auth_endpoint: oauth/authorize

1. ran npm run start
2. went to http://localhost:8000/admin
3. clicked Login with Gitlab, at which point I see:
   

in my on-prem Gitlab instance, the url is:

http://gitlab.sq.tlm.cloud/oauth/authorize?client_id=e60ead1dc7ff4266a4cecf35dfd82303cd1c6abc81610d04f96a115dac6965da&redirect_uri=http%3A%2F%2Flocalhost%3A8000%2Fadmin%2F&response_type=token&scope=api&state=ff29269c-83b8-4a16-9652-2722fb934794

I am not sure at all why it is not working. The couple things I have noticed and tried:

1. I tried navigating to http://localhost:9000/admin/ and I get this:
   

2. the redirect url in the big url above, when the application redirects me says redirect_uri=http%3A%2F%2Flocalhost%3A8000%2Fadmin%2F - is that correct? I put localhost:9000 in the Gitlab settings, so I am not sure why it is not 9000 as the query parameter

3. In my Gitlab settings, am I supposed to put http://localhost:8000/admin/ or http://localhost:9000/admin/?
4. I tried changing the application setting for Redirect URI to be http://localhost:8000/admin/ but then I just get redirected to the Gitlab admin home screen

One strange thing, is this was working last week when I did the same thing and I came in this morning and now it is not working. I deleted everything and tried doing the whole process again and cannot seem to get it to work.

Is there something special on localhost that I need to do to set it up?

[blubberbo]

I solved the problem quite simply (100% my misunderstanding). I read the readme generated by the quick start and reread the following section:

To test the CMS locally, you'll need run a production build of the site:

$ npm run build
$ npm run serve

I also had to add enableIdentityWidget: false, beneath line 65 resolve: 'gatsby-plugin-netlify-cms', in the gatsby-config.js.

I set my redirect value to http://localhost:9000/admin/ and then did npm run build and npm run serve and it works perfectly.

cheers to the Netlify, Netlify CMS and Gatsby team for great products!